The purpose of this project is to investigate the mechanisms of sperm maturation in the mammalian epididymis and vas deferens. Three specific projects will be studied: 1. Synthesis and secretion of glycoproteins along the epididymis using autoradiography as well as biochemical identification of the synthesized compounds. 2. An investigation of blood supply and function of the vas deferens. 3. The physiology and morphology of transepithelial water and electrolyte movements in the ductuli efferentes and initial segment.